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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.orchestra.conversation;
20  
21  import java.util.HashSet;
22  import java.util.Set;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  
27  import org.apache.myfaces.orchestra.conversation.basic.LogConversationMessager;
28  import org.apache.myfaces.orchestra.frameworkAdapter.FrameworkAdapter;
29  import org.apache.myfaces.orchestra.frameworkAdapter.local.LocalFrameworkAdapter;
30  
31  /**
32   * The ConversationWiperThread will trigger the conversation timeout check.
33   * <p>
34   * This is typically started from a servlet session listener when the webapp starts.
35   * 
36   * @see org.apache.myfaces.orchestra.conversation.servlet.ConversationManagerSessionListener
37   */
38  public class ConversationWiperThread extends Thread
39  {
40      private final Log log = LogFactory.getLog(ConversationWiperThread.class);
41  
42      private final long checkTime;
43  
44      private Set conversationManagers = new HashSet();
45  
46      /**
47       * Constructor.
48       * 
49       * @param checkTime is interval in milliseconds between scans of the existing
50       * ConversationManagers to look for timeouts.
51       */
52      public ConversationWiperThread(long checkTime)
53      {
54          this.checkTime = checkTime;
55  
56          setDaemon(true);
57          setName(ConversationWiperThread.class.getName());
58      }
59  
60      /**
61       * Add a ConversationManager to check.
62       * 
63       * @since 1.1
64       */
65      public void addConversationManager(ConversationManager cm)
66      {
67          synchronized (conversationManagers)
68          {
69              conversationManagers.add(cm);
70          }
71      }
72  
73      /**
74       * Remove a ConversationManager from the list to check.
75       * 
76       * @since 1.1
77       */
78      public void removeConversationManager(ConversationManager cm)
79      {
80          synchronized (conversationManagers)
81          {
82              boolean found = conversationManagers.remove(cm);
83              if (!found)
84              {
85                  // sanity check: this should not happen.
86                  log.error("Conversation Manager not found in remove");
87              }
88          }
89      }
90  
91      public void run()
92      {
93          if (log.isDebugEnabled())
94          {
95              log.debug("ConversationWiperThread startup"); // NON-NLS
96          }
97          _run();
98          if (log.isDebugEnabled())
99          {
100             log.debug("ConversationWiperThread shtudown"); // NON-NLS
101         }
102     }
103 
104     private void _run()
105     {
106         // Set up a custom FrameworkAdapter for this thread, so other orchestra code used by this
107         // thread which expects one to exist will not throw NullPointerException.
108         FrameworkAdapter fa = new LocalFrameworkAdapter();
109         ConversationMessager conversationMessager = new LogConversationMessager();
110         fa.setConversationMessager(conversationMessager);
111         FrameworkAdapter.setCurrentInstance(fa);
112 
113         while (!isInterrupted())
114         {
115             ConversationManager[] managersArray;
116             synchronized (conversationManagers)
117             {
118                 managersArray = new ConversationManager[conversationManagers.size()];
119                 conversationManagers.toArray(managersArray);
120             }
121 
122             if (log.isDebugEnabled())
123             {
124                 log.debug("ConversationWiperThread running against " + managersArray.length + " instances.");
125             }
126 
127             for (int i = 0; i<managersArray.length; i++)
128             {
129                 ConversationManager conversationManager = managersArray[i];
130                 conversationManager.checkTimeouts();
131             }
132 
133             try
134             {
135                 Thread.sleep(checkTime);
136             }
137             catch (InterruptedException e)
138             {
139                 return;
140             }
141         }
142     }
143 }